Electric furnace.



Patented Apr. 16, 1912.

C. T. FULLER.,

ELECTRIC FUBNAGE.

APPLIUATION FILED Dnc. ao. 190s.

Inventor* Carl TFhller, b

Y u muy Witnesses v y WM' @fw 1i/z W7 fie' UNITED STATES Y OFFICE.

CARL T. FULLER, OIF-EAST ORANGE. NEW' JERSEY, .ASSIGNOR TO GENERALELTCTR-IC COMPANY, A CORPORATION OF NEW YORK.

ELECTRIC FURNACE.

Specification of Letters Patent.

Patented Apr. 16, 1912.

Divided and this application tiled December lie it known that i, CARL T.FULLER, a eitizen ot the United States, residing at Cast ()range,eom1t vot' Essex. State ot; New Jersey7 have invented eertain new and uur t'ulv[mprovementa in lileetrie lturnaeest ot' whieh the t'ollowing is aSpeeitieation.

M v present invention eompriees an apparat'un lsuitable for use in theproduetion ol 'retraetmwf' eleetrieal emuluetors. Aaut-li asineandeseent lamp lilaments, turnaee li aterst and the like.

Mit* improved apparatus comprises4 a tubular heater throng-h whiehhydrogen or other redueing gas ma}7 he passed and in whieh tilameut'eontaining boats may be ].\laeed. these boats being ot sueh nature andso constructed that the hydrogen is tree y'to aet on the tlanientxswithout danger that the latter will beeome contaminated b v carbon orother material vaporized in the iiurnaee.

lln the aeeompanying drawing` ltigure l is a eeetional elevation ot at'urnaee, partly diagrammatic. and Fig. Q is a perspeetive vien ot theshuttle or boat in which the filaments or threadI arer inelosed duringtreatment'.

The 'turnaee illustrated in ltig. 'l eom prises. a graphite heater tube1 supplied with enrrent through Suitable terminals 2 and and i'neloaedin a proteetive eoating l ol5 eote or other refractory material..W'ithin th s tube. a seeond tube 5 ma)7 be inserted and withdrawn.'lhiseet-.ond tube is con tinuously supplied with h vdrogen through arubber tube and Serves as a reeeptaele lor the boats orshuttlesftcontaining the nnit'erial to be treated. prefer that tuta` 5shouldhave a Small bore at the end eonneet' ing with the ruhber'tube t3and should have an enlargement at. the. end containing the. boat T.

The retraetory boat eonsista ot' a troughshaped member having Sidewallal 8 and a eentral web tt and having a lining olii-extraetor)Ymaterial l() consisting ot rutile or otl other materials hereinaftermentioned. A' post. 1l oll rutile is mounted atV one end ot the boat. toserve as au anehoring deviee lor the tlaments under tnreatnnfnt.`

My invention may be used and applied for mauxY purposes. ln latent.#929.578

granted to me July 27. 1905i on applieation tiled August 24, 190i', Ser.No. 390.048, tot

` dnetors.

whieh applic-ation this appueation ia a ruvision) l have t'leseribed in'detail its use as applied to the produetion ot' tungaten conln this.mode of emplovmenta. the tube 5' ia witlulrawn from the iinrnaee, thetilamentarv bodies or threads to be treated inthe t'urnae ari arrangedin bundles on arutile paeking l ot boat the boats are introdneed intothe tube 5. and the tube is returned to its position "within vthe heatertube l, a Stream ot' hydrogenthrough tube being n'laintained during thistime; The lamenta ry bodies in the boats are converted into puretungsteii threadbI or wires in a eonunirativel)Y Short time, and areIturther tired at Snell a high temperature and tor such a length ottimeas will eonuriletelwiY sinter and .shrink the tungsten threads or vireSand render them Suitabletor mount'- ing in lamps withoutfurthertreatment. 'lheee baking and tiring operations require not more thanabout'v eight"y minutes at a temperature otl about 1-1-75 to i550degrees eentigrade.

The unfavorable intluenee of earbon from .the heating members ot theturnaee during the tiring or high heat treatment can be guarded againstby the. use. of proper material -t'or the boat or shuttle illustrated inFig. 2 ot the d airing. In generaLI prefer that the boat' `shallconsist. of or eompriae a material haringl a high atlinity for carbon.,or at leaat. having as great'a tendency to absorb carbon as doithefilaments under treatment. Sueh a bod)v :iets as an absorbing shield totaire up any carbdn 'Vapor given ott by the turnaee tu e.

Ot the various materials used by me in constructing the boats, I haveobtained best. results with a carbon boat having a pat-lting ot rutileTi()2 the materials being arranged as shown in ltig. 2 of the drawing. thave also Sueeesst'nlly used carbon boats lined with powdered tungsten.Either rutile. lor powdered tungsten serves, by virtue ot its highatlinitzy tor earbon, to prot'eet the filaments trom whatever earbonvapor may be eirenlating through the tube. '.lhese. materials algoponaeas the very important requisite ot notv stieking to the filamentsor combining therewith. in this respeet being similar to powdered silieaWhieh l have aueeesatnlly used. and being. in my opinion41 `tar superiorto oxide of the earth metal@7 go complete shrinkage.

suoli as thorium, magnesium, cerium, etc. By the' use of materials whichdo not become j sticky', the filaments are free to move longitudinallyin the boats and are free to under- \Vhen treated as above described,they do undergo this shrinkage, and they attain an electrical resistanceWhich remains 'substantially' constant l throughout their normal life asfilaments in l 1 0/lamps, `This resistance is directly comparaing hasgreat commercial advantage in that it permits simultaneoustreatinent ofdozens 'oreven hundreds of filaments, and furthermore yields conductors,which, forany furnace run, 'are sure to be uniform in size, composition,and electrical properties,- and ,therefore adapted for use in seriesWithout previous sorting and Weighing or other calibiation.

Although I have in my patent above re- '25 -ferred to described myimproved apparatus in connection vgith a process for the production oftungsten conductors by reducing an Oxid with hydrogen andthen effectingcomn' plete shrinkage and sintering of the refrac- -0 "tory re'sidue,.itshould be understood that my invention is applicable to the productionof conductors of various other refractory Confesof this patent may beobtainedfor in said tube in the metalsand materials, such for instanceas molybdenum, boron, zirconium, tant-alum, titanium, graphite, orcompounds or alloys of any of these or `of other materials of the sanlegeneral refractory nature.

lVhat I claim as new and desii'e to secure by Letters Patent of theUnited States, is:

' l. The combination of a carbonaceous resistance tube, means forsupplying electrical energy thereto to heat the same, means forsupplying hydrogen to said tube, and a charge protecting boat heated bysaid tube, said boat consisting in'part of rutile.

Q. The combination with a carbon tube resistance heater, of means forcontinuously supplying yhydrogen thereto, and a charge protecting boatof carbon lined with rutile inclosed and heated by said-tube and alsoprotected by said hydrogen.

3. In an electricfuinace, the combination of a carbonaoeous tube, meansfor heating said tube, means for supplying hydrogen to one end o'f saidtube, and a refractory boat, having marked affinity for carbon, mountedpat-h of said hydrogen, said boat being open. l

Inwitness whereof, I have hereunto set my hand this 28th day ofDecember, 1908.

C. T. FULLER. Vitnesses:

J. H.,E`Liiii s, S. W. WmTEHEAD.

ve cents each, by addressing the "Commissioner of Patenti Washington, D.C.

